Late last night, Cliff Lee shocked the baseball world by spurning ridiculous contract offers from the Yankees and Rangers, rejoining the Philadelphia Phillies. Predictably, there are a lot of people marveling at the Phillies’ new rotation. Remember last year, when a lot of us were saying, “Wow, what if they kept Lee and Halladay?” Now we get to see it.

But this doesn’t mean doom and gloom for the rest of the National League. Let’s pump the brakes a bit — they’ll have a dominating foursome, but let’s not act like this is some unbeatable force that will steamroll their way through the postseason.

The easy comparison will be the Atlanta Braves of the early 1990s. Greg Maddux, John Smoltz, Tom Glavine, and Steve Avery would have been aces for any team in the league. Even before Maddux joined the Braves in 1993, they were flat-out dominating. That 1993 season might be one of the most dominating year by a rotation we’ve ever seen — Maddux posted an ERA+ of 172, Smoltz an ERA+ of 112, Glavine an ERA+ of 127, and Avery an ERA+ of 138 — and they didn’t even make the World Series. The strike shortened the 1994 season, and when they finally won the World Series in 1995, it was with Avery putting up a below-average season. In 1996, the Braves again won the NL pennant, and again failed to win the World Series with Avery posting another below-average (sub-100 ERA+) season.

The Braves had to reload in 1997, replacing Avery with Denny Neagle. That foursome turned out to be even more dominating than the 1993 group when you look at the ERA+ numbers: Smoltz 138, Glavine 141, Neagle 140, Maddux 189. And again, they lost in the NLCS. 1998? Not as good as the year before, but still a great rotation, and again — no NL pennant. As we hit the 2000s, Smoltz, Glavine, and Maddux all started to hit their early-to-mid 30s, and started to lose their effectiveness.

Take a look at the ages of the Phillies’ 2011 rotation. Roy Halladay will be in his age 34 season. Lee will be 32. Roy Oswalt will be 33. Hamels is the only one not in his 30s — he’s going to be 27 in 2011. Pitchers do seem to age better than they used to, but the window for the Phillies is much smaller than it was for those Braves teams. They can’t really afford to lose a short playoff series and say “alright, we’ll try it again next year, no problem” like the Braves were able to do.

Considering the team’s budget, they almost have to win the World Series in 2011 to make this thing work. The Braves showed that it doesn’t matter how dominating you are in the regular season — anything can and will happen in the playoffs. Let’s not forget why the Phillies were knocked out by the Giants in 2010. It wasn’t because they didn’t have enough starting pitching. It was because the offense left them in October. If that happens again, you could round out that Phillies rotation with Tim Lincecum or Zack Greinke and it wouldn’t matter.